Ziemba U.S. Pat. No. 3,286,689 discloses a device for applying adhesive to surfaces. A fluid pressure diaphragm, defining a rear wall of a receiving chamber, includes projecting portions, which are used to close off orifices located in a front wall of the receiving chamber. Means are included to seal individual orifices in order to control the flow of the adhesive.
Moen U.S. Pat. No. 3,991,917 discloses a selectively actuable flexible stem valve. A flexible valve stem extends from a valve stem holder to a valve seat, where a valve element normally engages the valve seat to close an outlet. External operator means are provided to laterally flex the valve stem and thereby open the outlet.
Warning, Jr. U.S. Pat. No. 4,582,231 discloses an apparatus for applying liquid. A contact applicator head is described, which includes a plurality of needle valves. The needle valves are spring biased into respective extrusion orifices. A rotary cam is used to retract the needles from the extrusion orifices to provide a positive closing force to close each associated needle valve whereby subsequent dripping or oozing of the liquid from the orifice is eliminated.
Rothen et al. U.S. Pat. No. 5,083,526 discloses a glue coating apparatus. The apparatus comprises a reservoir, an applicator head having a plurality of adjacent slit nozzles, and a multiple gear pump which has a separate pump connected to each of the slit nozzles via a respective channel. The apparatus further comprises an applicator valve for communicating with each of the channels and, when actuated, permitting the substance to flow from the gear pump to the respective slit nozzle. A separate return-flow valve is also provided to permit flow of the substance from the multiple gear pump to the reservoir when the respective applicator valve is not actuated.